Systems used for the removal of particulate matter from a fluid stream incorporating a dust collector are well known. Typically a dust collector or a baghouse is comprised of two sections, an inlet chamber and an outlet chamber separated by a metal plate, which is normally called a tubesheet. The tube sheet has several openings wherein cartridge assemblies is also known as cartridge filters are normally inserted from the outlet chamber side into the dirty inlet chamber portion. Filter assemblies are attached and sealed to the tubesheet requiring the fluid stream to be channeled through the filter assemblies prior to reaching the outlet chamber. To ensure that the particulate matter being filtered out of the fluid does not pass from the inlet chamber into the outlet chamber, leaks between the filter assembly and the tubesheet should be avoided. Therefore a seal is generally achieved by using a snap band as an interface between the tubesheet and the filter assembly. U.S. Pat. Nos. 6,858,052 and 5,746,792 describe the most common snap band systems and their application. The snap bands are normally comprised of an inter-flexible metal strap and a flexible outer cover normally made of material, which can be easily deformed to allow insertion into the tubesheet opening. The difficulty with the existing designs is that under normal operating conditions the filter assembly can lift from the tubesheet and break the seal between the inlet chamber 108 and the outlet chamber 110. Conditions which can cause the filter assembly to lift from the tubesheet include but are not limited to thermal variations in high temperature environments, vibrations, and operation of reverse flow pulsing to clean the loaded filter assemblies.
Therefore there is a need for a filter lock and sealing system which prevents unintentional lifting of the filter assemblies from the tubesheet and subsequent seal loss and optionally also provides a secondary seal between the snap band and the filter assemblies when excessive compression of the snap band creates a deleterious material set.